[linux-kernel-mentees,v5] Doc : fs : convert xfs.txt to ReST
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Message ID 20190702123040.GA30111@localhost
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  • [linux-kernel-mentees,v5] Doc : fs : convert xfs.txt to ReST
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Sheriff Esseson July 2, 2019, 12:30 p.m. UTC
Convert xfs.txt to ReST, rename and fix broken references, consequently.

Make the name "value" in "option=value" look like a variable (that it probably
is), by embedding in angle "<>" brackets, rather than something predifined
elsewhere. This is inline with the conventions in manuals.
 	
Also, make defaults of boolean options prefixed with "(*)". This is so that
options can be compressed to "[no]option" and on a single line, which renders
consistently and nicely in htmldocs.

lastly, enforce a "one option, one definition" policy to keep things
consistent and simple.


Signed-off-by: Sheriff Esseson <sheriffesseson@gmail.com>
---

v5 aims to comply with the guiding comments on its previous versions.

 Documentation/filesystems/dax.txt   |   2 +-
 Documentation/filesystems/index.rst |   5 +-
 Documentation/filesystems/xfs.rst   | 468 +++++++++++++++++++++++++++
 Documentation/filesystems/xfs.txt   | 470 ----------------------------
 MAINTAINERS                         |   2 +-
 5 files changed, 473 insertions(+), 474 deletions(-)
 create mode 100644 Documentation/filesystems/xfs.rst
 delete mode 100644 Documentation/filesystems/xfs.txt

Comments

Matthew Wilcox July 2, 2019, 3:04 p.m. UTC | #1
On Tue, Jul 02, 2019 at 01:30:40PM +0100, Sheriff Esseson wrote:
> +When mounting an XFS filesystem, the following options are accepted.  For
> +boolean mount options, the names with the "(*)" prefix is the default behaviour.
> +For example, take a behaviour enabled by default to be a one (1) or, a zero (0)
> +otherwise, ``(*)[no]default`` would be 0 while ``[no](*)default`` , a 1.
> -When mounting an XFS filesystem, the following options are accepted.
> -For boolean mount options, the names with the (*) suffix is the
> -default behaviour.

You seem to have reflowed all the text.  That means git no longer notices
it's a rename, and quite frankly the shorter lines that were in use were
better.  This is not an improvement; please undo it in the next version
(which you should not post for several days to accumulate more feedback).
Darrick J. Wong July 2, 2019, 3:15 p.m. UTC | #2
On Tue, Jul 02, 2019 at 08:04:52AM -0700, Matthew Wilcox wrote:
> On Tue, Jul 02, 2019 at 01:30:40PM +0100, Sheriff Esseson wrote:
> > +When mounting an XFS filesystem, the following options are accepted.  For
> > +boolean mount options, the names with the "(*)" prefix is the default behaviour.
> > +For example, take a behaviour enabled by default to be a one (1) or, a zero (0)
> > +otherwise, ``(*)[no]default`` would be 0 while ``[no](*)default`` , a 1.
> > -When mounting an XFS filesystem, the following options are accepted.
> > -For boolean mount options, the names with the (*) suffix is the
> > -default behaviour.
> 
> You seem to have reflowed all the text.  That means git no longer notices
> it's a rename, and quite frankly the shorter lines that were in use were
> better.

Agreed.  Please don't reflow text in a format conversion patch, it makes
it very difficult to figure out which changes were to accomodate rst.

If you want to reflow text (because of line length etc.) please do it as
a second patch.  I'd rather break the 80 column rule for a single commit
if it makes reviewing easy on the eyes.

> This is not an improvement; please undo it in the next version
> (which you should not post for several days to accumulate more feedback).

Seconded.  Thank you for sending v5 as a separate patch, though. :)

--D
Matthew Wilcox July 2, 2019, 3:15 p.m. UTC | #3
On Tue, Jul 02, 2019 at 01:30:40PM +0100, Sheriff Esseson wrote:
> +++ b/Documentation/filesystems/index.rst
> @@ -40,4 +40,5 @@ Documentation for individual filesystem types can be found here.
>  .. toctree::
>     :maxdepth: 2
>  
> -   binderfs.rst
> +   binderfs
> +   xfs

I don't think this makes sense.  Look:

Kernel API documentation
------------------------
...
   filesystems/index

but the contents of xfs.rst are not kernel API documentation.  We have
precedent in Documentation/index.rst for:

Filesystem Documentation
------------------------

The documentation in this section are provided by specific filesystem
subprojects.

.. toctree::
   :maxdepth: 2

   filesystems/ext4/index

but that looks more like the xfs-delayed-logging-design.txt and
xfs-self-describing-metadata.txt files.

I think Documentation/filesystems/xfs.rst should be part of the
admin guide.  Furtnately, ext4 has again led the way here, and
Documentation/admin-guide/ext4.rst already exists.
Darrick J. Wong July 2, 2019, 3:22 p.m. UTC | #4
On Tue, Jul 02, 2019 at 01:30:40PM +0100, Sheriff Esseson wrote:
> Convert xfs.txt to ReST, rename and fix broken references, consequently.
> 
> Make the name "value" in "option=value" look like a variable (that it probably
> is), by embedding in angle "<>" brackets, rather than something predifined
> elsewhere. This is inline with the conventions in manuals.
>  	
> Also, make defaults of boolean options prefixed with "(*)". This is so that
> options can be compressed to "[no]option" and on a single line, which renders
> consistently and nicely in htmldocs.
> 
> lastly, enforce a "one option, one definition" policy to keep things
> consistent and simple.
> 
> 
> Signed-off-by: Sheriff Esseson <sheriffesseson@gmail.com>
> ---
> 
> v5 aims to comply with the guiding comments on its previous versions.
> 
>  Documentation/filesystems/dax.txt   |   2 +-
>  Documentation/filesystems/index.rst |   5 +-
>  Documentation/filesystems/xfs.rst   | 468 +++++++++++++++++++++++++++
>  Documentation/filesystems/xfs.txt   | 470 ----------------------------
>  MAINTAINERS                         |   2 +-
>  5 files changed, 473 insertions(+), 474 deletions(-)
>  create mode 100644 Documentation/filesystems/xfs.rst
>  delete mode 100644 Documentation/filesystems/xfs.txt
> 
> diff --git a/Documentation/filesystems/dax.txt b/Documentation/filesystems/dax.txt
> index 6d2c0d340..c333285b8 100644
> --- a/Documentation/filesystems/dax.txt
> +++ b/Documentation/filesystems/dax.txt
> @@ -76,7 +76,7 @@ exposure of uninitialized data through mmap.
>  These filesystems may be used for inspiration:
>  - ext2: see Documentation/filesystems/ext2.txt
>  - ext4: see Documentation/filesystems/ext4/
> -- xfs:  see Documentation/filesystems/xfs.txt
> +- xfs:  see Documentation/filesystems/xfs.rst
>  
>  
>  Handling Media Errors
> diff --git a/Documentation/filesystems/index.rst b/Documentation/filesystems/index.rst
> index 1131c34d7..a4cf5fca4 100644
> --- a/Documentation/filesystems/index.rst
> +++ b/Documentation/filesystems/index.rst
> @@ -16,7 +16,7 @@ algorithms work.
>  .. toctree::
>     :maxdepth: 2
>  
> -   path-lookup.rst
> +   path-lookup
>     api-summary
>     splice
>  
> @@ -40,4 +40,5 @@ Documentation for individual filesystem types can be found here.
>  .. toctree::
>     :maxdepth: 2
>  
> -   binderfs.rst
> +   binderfs
> +   xfs
> diff --git a/Documentation/filesystems/xfs.rst b/Documentation/filesystems/xfs.rst
> new file mode 100644
> index 000000000..d36ef042c
> --- /dev/null
> +++ b/Documentation/filesystems/xfs.rst
> @@ -0,0 +1,468 @@
> +.. SPDX-License-Identifier: GPL-2.0
> +======================
> +The SGI XFS Filesystem
> +======================
> +
> +XFS is a high performance journaling filesystem which originated
> +on the SGI IRIX platform.  It is completely multi-threaded, can
> +support large files and large filesystems, extended attributes,
> +variable block sizes, is extent based, and makes extensive use of
> +Btrees (directories, extents, free space) to aid both performance
> +and scalability.
> +
> +Refer to the documentation at https://xfs.wiki.kernel.org/
> +for further details.  This implementation is on-disk compatible
> +with the IRIX version of XFS.
> +
> +
> +Mount Options
> +=============
> +
> +When mounting an XFS filesystem, the following options are accepted.  For
> +boolean mount options, the names with the "(*)" prefix is the default behaviour.
> +For example, take a behaviour enabled by default to be a one (1) or, a zero (0)
> +otherwise, ``(*)[no]default`` would be 0 while ``[no](*)default`` , a 1.

That's really confusing.  Does this mean that I can pass discard=1 now?

(no)

I also don't really understand why we need to cram so much into a single
line.  Why not just:

    discard
    nodiscard (default)
	Something something discard chomps on free space, chomp chomp
	a chewy chomp, pretend I wrote the real text here, etc.

Or if you really want the single-line header...

    [no]discard
	Something something discard chomps on free space, chomp chomp
	a chewy chomp, pretend I wrote the real text here, etc.

	''nodiscard'' is the default setting.

Please don't introduce '1's and '0's here because there are other parts
of xfs where you /can/ enable or disable features by saying "foo=0" or
"foo=1".

There's probably more to say but the text reflowing since v1 makes this
patch unreviewable because ugh 1000-line diff.

--D

> +
> +   allocsize=<size>
> +        Sets the buffered I/O end-of-file preallocation size when doing delayed
> +        allocation writeout (default size is 64KiB).  Valid values for this
> +        option are page size (typically 4KiB) through to 1GiB, inclusive, in
> +        power-of-2 increments.
> +
> +        The default behaviour is for dynamic end-of-file preallocation size,
> +        which uses a set of heuristics to optimise the preallocation size based
> +        on the current allocation patterns within the file and the access
> +        patterns to the file. Specifying a fixed allocsize value turns off the
> +        dynamic behaviour.
> +
> +   [no]attr2
> +        The options enable/disable an "opportunistic" improvement to be made in
> +        the way inline extended attributes are stored on-disk.  When the new
> +        form is used for the first time when ``attr2`` is selected (either when
> +        setting or removing extended attributes) the on-disk superblock feature
> +        bit field will be updated to reflect this format being in use.
> +
> +        The default behaviour is determined by the on-disk feature bit
> +        indicating that ``attr2`` behaviour is active. If either mount option is
> +        set, then that becomes the new default used by the filesystem. However
> +        on CRC enabled filesystems, the ``attr2`` format is always used , and so
> +        will reject the ``noattr2`` mount option if it is set.
> +
> +   (*)[no]discard
> +        Enable/disable the issuing of commands to let the block device reclaim
> +        space freed by the filesystem.  This is useful for SSD devices, thinly
> +        provisioned LUNs and virtual machine images, but may have a performance
> +        impact.
> +
> +        Note: It is currently recommended that you use the ``fstrim``
> +        application to discard unused blocks rather than the ``discard`` mount
> +        option because the performance impact of this option is quite severe.
> +
> +   grpid/bsdgroups
> +   nogrpid/(*)sysvgroups
> +        These options define what group ID a newly created file gets.  When
> +        ``grpid`` is set, it takes the group ID of the directory in which it is
> +        created; otherwise it takes the ``fsgid`` of the current process, unless
> +        the directory has the ``setgid`` bit set, in which case it takes the
> +        ``gid`` from the parent directory, and also gets the ``setgid`` bit set
> +        if it is a directory itself.
> +
> +   filestreams
> +        Make the data allocator use the filestreams allocation mode across the
> +        entire filesystem rather than just on directories configured to use it.
> +
> +   (*)[no]ikeep
> +        When ``ikeep`` is specified, XFS does not delete empty inode clusters
> +        and keeps them around on disk.  When ``noikeep`` is specified, empty
> +        inode clusters are returned to the free space pool.
> +
> +   inode32 | (*)inode64
> +        When ``inode32`` is specified, it indicates that XFS limits inode
> +        creation to locations which will not result in inode numbers with more
> +        than 32 bits of significance.
> +
> +        When ``inode64`` is specified, it indicates that XFS is allowed to
> +        create inodes at any location in the filesystem, including those which
> +        will result in inode numbers occupying more than 32 bits of
> +        significance.
> +
> +        ``inode32`` is provided for backwards compatibility with older systems
> +        and applications, since 64 bits inode numbers might cause problems for
> +        some applications that cannot handle large inode numbers.  If
> +        applications are in use which do not handle inode numbers bigger than 32
> +        bits, the ``inode32`` option should be specified.
> +
> +
> +   (*)[no]largeio
> +        If ``nolargeio`` is specified, the optimal I/O reported in st_blksize by
> +        **stat(2)** will be as small as possible to allow user applications to
> +        avoid inefficient read/modify/write I/O.  This is typically the page
> +        size of the machine, as this is the granularity of the page cache.
> +
> +        If ``largeio`` is specified, a filesystem that was created with a
> +        ``swidth`` specified will return the ``swidth`` value (in bytes) in
> +        st_blksize. If the filesystem does not have a ``swidth`` specified but
> +        does specify an ``allocsize`` then ``allocsize`` (in bytes) will be
> +        returned instead. Otherwise the behaviour is the same as if
> +        ``nolargeio`` was specified.
> +
> +   logbufs=<value>
> +        Set the number of in-memory log buffers to ``value``.  Valid numbers
> +        range from 2-8 inclusive.
> +
> +        The default value is 8 buffers.
> +
> +        If the memory cost of 8 log buffers is too high on small systems, then
> +        it may be reduced at some cost to performance on metadata intensive
> +        workloads. The ``logbsize`` option below controls the size of each
> +        buffer and so is also relevant to this case.
> +
> +   logbsize=<value>
> +        Set the size of each in-memory log buffer to ``value``.  The size may be
> +        specified in bytes, or in kilobytes with a "k" suffix. Valid sizes for
> +        version 1 and version 2 logs are 16384 (16k) and 32768 (32k).  Valid
> +        sizes for version 2 logs also include 65536 (64k), 131072 (128k) and
> +        262144 (256k). The ``logbsize`` must be an integer multiple of the
> +        "log stripe unit" configured at mkfs time.
> +
> +        The default value for for version 1 logs is 32768, while the default
> +        value for version 2 logs is ``MAX(32768, log_sunit)``.
> +
> +   logdev=<device>
> +        Use ``device`` as an external log (metadata journal).  In an XFS
> +        filesystem, the log device can be separate from the data device or
> +        contained within it.
> +
> +   rtdev=<device>
> +        An XFS filesystem has up to three parts: a data section, a log section,
> +        and a real-time section.  The real-time section is optional.  If
> +        enabled, ``rtdev`` sets ``device`` to be used as an external real-time
> +        section, similar to ``logdev`` above.
> +
> +   noalign
> +        Data allocations will not be aligned at stripe unit boundaries. This is
> +        only relevant to filesystems created with non-zero data alignment
> +        parameters (sunit, swidth) by mkfs.
> +
> +   norecovery
> +        The filesystem will be mounted without running log recovery.  If the
> +        filesystem was not cleanly unmounted, it is likely to be inconsistent
> +        when mounted in ``norecovery`` mode.  Some files or directories may not
> +        be accessible because of this.  Filesystems mounted ``norecovery`` must
> +        be mounted read-only or the mount will fail.
> +
> +   nouuid
> +        Don't check for double mounted file systems using the file system uuid.
> +        This is useful to mount LVM snapshot volumes, and often used in
> +        combination with ``norecovery`` for mounting read-only snapshots.
> +
> +   noquota
> +	Forcibly turns off all quota accounting and enforcement
> +	within the filesystem.
> +
> +   uquota/usrquota/uqnoenforce/quota
> +        User disk quota accounting enabled, and limits (optionally) enforced.
> +        Refer to **xfs_quota(8)** for further details.
> +
> +   gquota/grpquota/gqnoenforce
> +        Group disk quota accounting enabled and limits (optionally) enforced.
> +        Refer to **xfs_quota(8)** for further details.
> +
> +   pquota/prjquota/pqnoenforce
> +        Project disk quota accounting enabled and limits (optionally) enforced.
> +        Refer to **xfs_quota(8)** for further details.
> +
> +   sunit=<value>
> +        Used to specify the stripe unit for a RAID device or (in conjunction
> +        with ``swidth`` below) a stripe volume.  ``value`` must be specified in
> +        512-byte block units. This option is only relevant to filesystems that
> +        were created with non-zero data alignment parameters.
> +
> +        The ``sunit`` parameter specified must be compatible with the existing
> +        filesystem alignment characteristics.  In general, that means the only
> +        valid changes to ``sunit`` are increasing it by a power-of-2 multiple.
> +
> +        Typically, this mount option is necessary only after an underlying RAID
> +        device has had its geometry modified, such as adding a new disk to a
> +        RAID5 lun and reshaping it.
> +
> +   swidth=<value>
> +        Used to specify the stripe width for a RAID device or (in conjunction
> +        with ``sunit`` above) a stripe volume.  ``value`` must be specified in
> +        512-byte block units. This option, like ``sunit`` above, is only
> +        relevant to filesystems that were created with non-zero data alignment
> +        parameters.
> +
> +        The ``swidth`` parameter specified must be compatible with the existing
> +        filesystem alignment characteristics.  In general, that means the only
> +        valid swidth values are any integer multiple of a valid ``sunit`` value.
> +
> +        Typically, this mount option is necessary only after an underlying RAID
> +        device has had its geometry modified, such as adding a new disk to a
> +        RAID5 lun and reshaping it.
> +
> +
> +   swalloc
> +        Data allocations will be rounded up to stripe width boundaries when the
> +        current end of file is being extended and the file size is larger than
> +        the stripe width size.
> +
> +   wsync
> +        When specified, all filesystem namespace operations are executed
> +        synchronously. This ensures that when the namespace operation (create,
> +        unlink, etc) completes, the change to the namespace is on stable
> +        storage. This is useful in HA setups where failover must not result in
> +        clients seeing inconsistent namespace presentation during or after a
> +        failover event.
> +
> +
> +Deprecated Mount Options
> +========================
> +
> +  Name				Removal Schedule
> +  ----				----------------
> +
> +
> +Removed Mount Options
> +=====================
> +
> +  Name				Removed
> +  ----				-------
> +  delaylog/nodelaylog		v4.0
> +  ihashsize			v4.0
> +  irixsgid			v4.0
> +  osyncisdsync/osyncisosync	v4.0
> +  barrier			v4.19
> +  nobarrier			v4.19
> +
> +
> +sysctls
> +=======
> +
> +The following sysctls are available for the XFS filesystem:
> +
> +  fs.xfs.stats_clear		(Min: 0  Default: 0  Max: 1)
> +	Setting this to "1" clears accumulated XFS statistics
> +	in /proc/fs/xfs/stat.  It then immediately resets to "0".
> +
> +  fs.xfs.xfssyncd_centisecs	(Min: 100  Default: 3000  Max: 720000)
> +	The interval at which the filesystem flushes metadata
> +	out to disk and runs internal cache cleanup routines.
> +
> +  fs.xfs.filestream_centisecs	(Min: 1  Default: 3000  Max: 360000)
> +	The interval at which the filesystem ages filestreams cache
> +	references and returns timed-out AGs back to the free stream
> +	pool.
> +
> +  fs.xfs.speculative_prealloc_lifetime
> +		(Units: seconds   Min: 1  Default: 300  Max: 86400)
> +	The interval at which the background scanning for inodes
> +	with unused speculative preallocation runs. The scan
> +	removes unused preallocation from clean inodes and releases
> +	the unused space back to the free pool.
> +
> +  fs.xfs.error_level		(Min: 0  Default: 3  Max: 11)
> +	A volume knob for error reporting when internal errors occur.
> +	This will generate detailed messages & backtraces for filesystem
> +	shutdowns, for example.  Current threshold values are:
> +
> +		XFS_ERRLEVEL_OFF:       0
> +		XFS_ERRLEVEL_LOW:       1
> +		XFS_ERRLEVEL_HIGH:      5
> +
> +  fs.xfs.panic_mask		(Min: 0  Default: 0  Max: 256)
> +	Causes certain error conditions to call BUG(). Value is a bitmask;
> +	OR together the tags which represent errors which should cause panics:
> +
> +		XFS_NO_PTAG                     0
> +		XFS_PTAG_IFLUSH                 0x00000001
> +		XFS_PTAG_LOGRES                 0x00000002
> +		XFS_PTAG_AILDELETE              0x00000004
> +		XFS_PTAG_ERROR_REPORT           0x00000008
> +		XFS_PTAG_SHUTDOWN_CORRUPT       0x00000010
> +		XFS_PTAG_SHUTDOWN_IOERROR       0x00000020
> +		XFS_PTAG_SHUTDOWN_LOGERROR      0x00000040
> +		XFS_PTAG_FSBLOCK_ZERO           0x00000080
> +		XFS_PTAG_VERIFIER_ERROR         0x00000100
> +
> +	This option is intended for debugging only.
> +
> +  fs.xfs.irix_symlink_mode	(Min: 0  Default: 0  Max: 1)
> +	Controls whether symlinks are created with mode 0777 (default)
> +	or whether their mode is affected by the umask (irix mode).
> +
> +  fs.xfs.irix_sgid_inherit	(Min: 0  Default: 0  Max: 1)
> +	Controls files created in SGID directories.
> +	If the group ID of the new file does not match the effective group
> +	ID or one of the supplementary group IDs of the parent dir, the
> +	ISGID bit is cleared if the irix_sgid_inherit compatibility sysctl
> +	is set.
> +
> +  fs.xfs.inherit_sync		(Min: 0  Default: 1  Max: 1)
> +	Setting this to "1" will cause the "sync" flag set
> +	by the **xfs_io(8)** chattr command on a directory to be
> +	inherited by files in that directory.
> +
> +  fs.xfs.inherit_nodump		(Min: 0  Default: 1  Max: 1)
> +	Setting this to "1" will cause the "nodump" flag set
> +	by the **xfs_io(8)** chattr command on a directory to be
> +	inherited by files in that directory.
> +
> +  fs.xfs.inherit_noatime	(Min: 0  Default: 1  Max: 1)
> +	Setting this to "1" will cause the "noatime" flag set
> +	by the **xfs_io(8)** chattr command on a directory to be
> +	inherited by files in that directory.
> +
> +  fs.xfs.inherit_nosymlinks	(Min: 0  Default: 1  Max: 1)
> +	Setting this to "1" will cause the "nosymlinks" flag set
> +	by the **xfs_io(8)** chattr command on a directory to be
> +	inherited by files in that directory.
> +
> +  fs.xfs.inherit_nodefrag	(Min: 0  Default: 1  Max: 1)
> +	Setting this to "1" will cause the "nodefrag" flag set
> +	by the **xfs_io(8)** chattr command on a directory to be
> +	inherited by files in that directory.
> +
> +  fs.xfs.rotorstep		(Min: 1  Default: 1  Max: 256)
> +	In "inode32" allocation mode, this option determines how many
> +	files the allocator attempts to allocate in the same allocation
> +	group before moving to the next allocation group.  The intent
> +	is to control the rate at which the allocator moves between
> +	allocation groups when allocating extents for new files.
> +
> +Deprecated Sysctls
> +==================
> +
> +None at present.
> +
> +
> +Removed Sysctls
> +===============
> +
> +  Name				Removed
> +  ----				-------
> +  fs.xfs.xfsbufd_centisec	v4.0
> +  fs.xfs.age_buffer_centisecs	v4.0
> +
> +
> +Error handling
> +==============
> +
> +XFS can act differently according to the type of error found during its
> +operation. The implementation introduces the following concepts to the error
> +handler:
> +
> + -failure speed:
> +	Defines how fast XFS should propagate an error upwards when a specific
> +	error is found during the filesystem operation. It can propagate
> +	immediately, after a defined number of retries, after a set time period,
> +	or simply retry forever.
> +
> + -error classes:
> +	Specifies the subsystem the error configuration will apply to, such as
> +	metadata IO or memory allocation. Different subsystems will have
> +	different error handlers for which behaviour can be configured.
> +
> + -error handlers:
> +	Defines the behavior for a specific error.
> +
> +The filesystem behavior during an error can be set via sysfs files. Each
> +error handler works independently - the first condition met by an error handler
> +for a specific class will cause the error to be propagated rather than reset and
> +retried.
> +
> +The action taken by the filesystem when the error is propagated is context
> +dependent - it may cause a shut down in the case of an unrecoverable error,
> +it may be reported back to userspace, or it may even be ignored because
> +there's nothing useful we can with the error or anyone we can report it to (e.g.
> +during unmount).
> +
> +The configuration files are organized into the following hierarchy for each
> +mounted filesystem:
> +
> +  /sys/fs/xfs/<dev>/error/<class>/<error>/
> +
> +Where:
> +  <dev>
> +	The short device name of the mounted filesystem. This is the same device
> +	name that shows up in XFS kernel error messages as "XFS(<dev>): ..."
> +
> +  <class>
> +	The subsystem the error configuration belongs to. As of 4.9, the defined
> +	classes are:
> +
> +		- "metadata": applies metadata buffer write IO
> +
> +  <error>
> +	The individual error handler configurations.
> +
> +
> +Each filesystem has "global" error configuration options defined in their top
> +level directory:
> +
> +  /sys/fs/xfs/<dev>/error/
> +
> +  fail_at_unmount		(Min:  0  Default:  1  Max: 1)
> +	Defines the filesystem error behavior at unmount time.
> +
> +	If set to a value of 1, XFS will override all other error configurations
> +	during unmount and replace them with "immediate fail" characteristics.
> +	i.e. no retries, no retry timeout. This will always allow unmount to
> +	succeed when there are persistent errors present.
> +
> +	If set to 0, the configured retry behaviour will continue until all
> +	retries and/or timeouts have been exhausted. This will delay unmount
> +	completion when there are persistent errors, and it may prevent the
> +	filesystem from ever unmounting fully in the case of "retry forever"
> +	handler configurations.
> +
> +	Note: there is no guarantee that fail_at_unmount can be set while an
> +	unmount is in progress. It is possible that the sysfs entries are
> +	removed by the unmounting filesystem before a "retry forever" error
> +	handler configuration causes unmount to hang, and hence the filesystem
> +	must be configured appropriately before unmount begins to prevent
> +	unmount hangs.
> +
> +Each filesystem has specific error class handlers that define the error
> +propagation behaviour for specific errors. There is also a "default" error
> +handler defined, which defines the behaviour for all errors that don't have
> +specific handlers defined. Where multiple retry constraints are configuredi for
> +a single error, the first retry configuration that expires will cause the error
> +to be propagated. The handler configurations are found in the directory:
> +
> +  /sys/fs/xfs/<dev>/error/<class>/<error>/
> +
> +  max_retries			(Min: -1  Default: Varies  Max: INTMAX)
> +	Defines the allowed number of retries of a specific error before
> +	the filesystem will propagate the error. The retry count for a given
> +	error context (e.g. a specific metadata buffer) is reset every time
> +	there is a successful completion of the operation.
> +
> +	Setting the value to "-1" will cause XFS to retry forever for this
> +	specific error.
> +
> +	Setting the value to "0" will cause XFS to fail immediately when the
> +	specific error is reported.
> +
> +	Setting the value to "N" (where 0 < N < Max) will make XFS retry the
> +	operation "N" times before propagating the error.
> +
> +  retry_timeout_seconds		(Min:  -1  Default:  Varies  Max: 1 day)
> +	Define the amount of time (in seconds) that the filesystem is
> +	allowed to retry its operations when the specific error is
> +	found.
> +
> +	Setting the value to "-1" will allow XFS to retry forever for this
> +	specific error.
> +
> +	Setting the value to "0" will cause XFS to fail immediately when the
> +	specific error is reported.
> +
> +	Setting the value to "N" (where 0 < N < Max) will allow XFS to retry the
> +	operation for up to "N" seconds before propagating the error.
> +
> +Note: The default behaviour for a specific error handler is dependent on both
> +the class and error context. For example, the default values for
> +"metadata/ENODEV" are "0" rather than "-1" so that this error handler defaults
> +to "fail immediately" behaviour. This is done because ENODEV is a fatal,
> +unrecoverable error no matter how many times the metadata IO is retried.
> diff --git a/Documentation/filesystems/xfs.txt b/Documentation/filesystems/xfs.txt
> deleted file mode 100644
> index a5cbb5e0e..000000000
> --- a/Documentation/filesystems/xfs.txt
> +++ /dev/null
> @@ -1,470 +0,0 @@
> -
> -The SGI XFS Filesystem
> -======================
> -
> -XFS is a high performance journaling filesystem which originated
> -on the SGI IRIX platform.  It is completely multi-threaded, can
> -support large files and large filesystems, extended attributes,
> -variable block sizes, is extent based, and makes extensive use of
> -Btrees (directories, extents, free space) to aid both performance
> -and scalability.
> -
> -Refer to the documentation at https://xfs.wiki.kernel.org/
> -for further details.  This implementation is on-disk compatible
> -with the IRIX version of XFS.
> -
> -
> -Mount Options
> -=============
> -
> -When mounting an XFS filesystem, the following options are accepted.
> -For boolean mount options, the names with the (*) suffix is the
> -default behaviour.
> -
> -  allocsize=size
> -	Sets the buffered I/O end-of-file preallocation size when
> -	doing delayed allocation writeout (default size is 64KiB).
> -	Valid values for this option are page size (typically 4KiB)
> -	through to 1GiB, inclusive, in power-of-2 increments.
> -
> -	The default behaviour is for dynamic end-of-file
> -	preallocation size, which uses a set of heuristics to
> -	optimise the preallocation size based on the current
> -	allocation patterns within the file and the access patterns
> -	to the file. Specifying a fixed allocsize value turns off
> -	the dynamic behaviour.
> -
> -  attr2
> -  noattr2
> -	The options enable/disable an "opportunistic" improvement to
> -	be made in the way inline extended attributes are stored
> -	on-disk.  When the new form is used for the first time when
> -	attr2 is selected (either when setting or removing extended
> -	attributes) the on-disk superblock feature bit field will be
> -	updated to reflect this format being in use.
> -
> -	The default behaviour is determined by the on-disk feature
> -	bit indicating that attr2 behaviour is active. If either
> -	mount option it set, then that becomes the new default used
> -	by the filesystem.
> -
> -	CRC enabled filesystems always use the attr2 format, and so
> -	will reject the noattr2 mount option if it is set.
> -
> -  discard
> -  nodiscard (*)
> -	Enable/disable the issuing of commands to let the block
> -	device reclaim space freed by the filesystem.  This is
> -	useful for SSD devices, thinly provisioned LUNs and virtual
> -	machine images, but may have a performance impact.
> -
> -	Note: It is currently recommended that you use the fstrim
> -	application to discard unused blocks rather than the discard
> -	mount option because the performance impact of this option
> -	is quite severe.
> -
> -  grpid/bsdgroups
> -  nogrpid/sysvgroups (*)
> -	These options define what group ID a newly created file
> -	gets.  When grpid is set, it takes the group ID of the
> -	directory in which it is created; otherwise it takes the
> -	fsgid of the current process, unless the directory has the
> -	setgid bit set, in which case it takes the gid from the
> -	parent directory, and also gets the setgid bit set if it is
> -	a directory itself.
> -
> -  filestreams
> -	Make the data allocator use the filestreams allocation mode
> -	across the entire filesystem rather than just on directories
> -	configured to use it.
> -
> -  ikeep
> -  noikeep (*)
> -	When ikeep is specified, XFS does not delete empty inode
> -	clusters and keeps them around on disk.  When noikeep is
> -	specified, empty inode clusters are returned to the free
> -	space pool.
> -
> -  inode32
> -  inode64 (*)
> -	When inode32 is specified, it indicates that XFS limits
> -	inode creation to locations which will not result in inode
> -	numbers with more than 32 bits of significance.
> -
> -	When inode64 is specified, it indicates that XFS is allowed
> -	to create inodes at any location in the filesystem,
> -	including those which will result in inode numbers occupying
> -	more than 32 bits of significance. 
> -
> -	inode32 is provided for backwards compatibility with older
> -	systems and applications, since 64 bits inode numbers might
> -	cause problems for some applications that cannot handle
> -	large inode numbers.  If applications are in use which do
> -	not handle inode numbers bigger than 32 bits, the inode32
> -	option should be specified.
> -
> -
> -  largeio
> -  nolargeio (*)
> -	If "nolargeio" is specified, the optimal I/O reported in
> -	st_blksize by stat(2) will be as small as possible to allow
> -	user applications to avoid inefficient read/modify/write
> -	I/O.  This is typically the page size of the machine, as
> -	this is the granularity of the page cache.
> -
> -	If "largeio" specified, a filesystem that was created with a
> -	"swidth" specified will return the "swidth" value (in bytes)
> -	in st_blksize. If the filesystem does not have a "swidth"
> -	specified but does specify an "allocsize" then "allocsize"
> -	(in bytes) will be returned instead. Otherwise the behaviour
> -	is the same as if "nolargeio" was specified.
> -
> -  logbufs=value
> -	Set the number of in-memory log buffers.  Valid numbers
> -	range from 2-8 inclusive.
> -
> -	The default value is 8 buffers.
> -
> -	If the memory cost of 8 log buffers is too high on small
> -	systems, then it may be reduced at some cost to performance
> -	on metadata intensive workloads. The logbsize option below
> -	controls the size of each buffer and so is also relevant to
> -	this case.
> -
> -  logbsize=value
> -	Set the size of each in-memory log buffer.  The size may be
> -	specified in bytes, or in kilobytes with a "k" suffix.
> -	Valid sizes for version 1 and version 2 logs are 16384 (16k)
> -	and 32768 (32k).  Valid sizes for version 2 logs also
> -	include 65536 (64k), 131072 (128k) and 262144 (256k). The
> -	logbsize must be an integer multiple of the log
> -	stripe unit configured at mkfs time.
> -
> -	The default value for for version 1 logs is 32768, while the
> -	default value for version 2 logs is MAX(32768, log_sunit).
> -
> -  logdev=device and rtdev=device
> -	Use an external log (metadata journal) and/or real-time device.
> -	An XFS filesystem has up to three parts: a data section, a log
> -	section, and a real-time section.  The real-time section is
> -	optional, and the log section can be separate from the data
> -	section or contained within it.
> -
> -  noalign
> -	Data allocations will not be aligned at stripe unit
> -	boundaries. This is only relevant to filesystems created
> -	with non-zero data alignment parameters (sunit, swidth) by
> -	mkfs.
> -
> -  norecovery
> -	The filesystem will be mounted without running log recovery.
> -	If the filesystem was not cleanly unmounted, it is likely to
> -	be inconsistent when mounted in "norecovery" mode.
> -	Some files or directories may not be accessible because of this.
> -	Filesystems mounted "norecovery" must be mounted read-only or
> -	the mount will fail.
> -
> -  nouuid
> -	Don't check for double mounted file systems using the file
> -	system uuid.  This is useful to mount LVM snapshot volumes,
> -	and often used in combination with "norecovery" for mounting
> -	read-only snapshots.
> -
> -  noquota
> -	Forcibly turns off all quota accounting and enforcement
> -	within the filesystem.
> -
> -  uquota/usrquota/uqnoenforce/quota
> -	User disk quota accounting enabled, and limits (optionally)
> -	enforced.  Refer to xfs_quota(8) for further details.
> -
> -  gquota/grpquota/gqnoenforce
> -	Group disk quota accounting enabled and limits (optionally)
> -	enforced.  Refer to xfs_quota(8) for further details.
> -
> -  pquota/prjquota/pqnoenforce
> -	Project disk quota accounting enabled and limits (optionally)
> -	enforced.  Refer to xfs_quota(8) for further details.
> -
> -  sunit=value and swidth=value
> -	Used to specify the stripe unit and width for a RAID device
> -	or a stripe volume.  "value" must be specified in 512-byte
> -	block units. These options are only relevant to filesystems
> -	that were created with non-zero data alignment parameters.
> -
> -	The sunit and swidth parameters specified must be compatible
> -	with the existing filesystem alignment characteristics.  In
> -	general, that means the only valid changes to sunit are
> -	increasing it by a power-of-2 multiple. Valid swidth values
> -	are any integer multiple of a valid sunit value.
> -
> -	Typically the only time these mount options are necessary if
> -	after an underlying RAID device has had it's geometry
> -	modified, such as adding a new disk to a RAID5 lun and
> -	reshaping it.
> -
> -  swalloc
> -	Data allocations will be rounded up to stripe width boundaries
> -	when the current end of file is being extended and the file
> -	size is larger than the stripe width size.
> -
> -  wsync
> -	When specified, all filesystem namespace operations are
> -	executed synchronously. This ensures that when the namespace
> -	operation (create, unlink, etc) completes, the change to the
> -	namespace is on stable storage. This is useful in HA setups
> -	where failover must not result in clients seeing
> -	inconsistent namespace presentation during or after a
> -	failover event.
> -
> -
> -Deprecated Mount Options
> -========================
> -
> -  Name				Removal Schedule
> -  ----				----------------
> -
> -
> -Removed Mount Options
> -=====================
> -
> -  Name				Removed
> -  ----				-------
> -  delaylog/nodelaylog		v4.0
> -  ihashsize			v4.0
> -  irixsgid			v4.0
> -  osyncisdsync/osyncisosync	v4.0
> -  barrier			v4.19
> -  nobarrier			v4.19
> -
> -
> -sysctls
> -=======
> -
> -The following sysctls are available for the XFS filesystem:
> -
> -  fs.xfs.stats_clear		(Min: 0  Default: 0  Max: 1)
> -	Setting this to "1" clears accumulated XFS statistics
> -	in /proc/fs/xfs/stat.  It then immediately resets to "0".
> -
> -  fs.xfs.xfssyncd_centisecs	(Min: 100  Default: 3000  Max: 720000)
> -	The interval at which the filesystem flushes metadata
> -	out to disk and runs internal cache cleanup routines.
> -
> -  fs.xfs.filestream_centisecs	(Min: 1  Default: 3000  Max: 360000)
> -	The interval at which the filesystem ages filestreams cache
> -	references and returns timed-out AGs back to the free stream
> -	pool.
> -
> -  fs.xfs.speculative_prealloc_lifetime
> -		(Units: seconds   Min: 1  Default: 300  Max: 86400)
> -	The interval at which the background scanning for inodes
> -	with unused speculative preallocation runs. The scan
> -	removes unused preallocation from clean inodes and releases
> -	the unused space back to the free pool.
> -
> -  fs.xfs.error_level		(Min: 0  Default: 3  Max: 11)
> -	A volume knob for error reporting when internal errors occur.
> -	This will generate detailed messages & backtraces for filesystem
> -	shutdowns, for example.  Current threshold values are:
> -
> -		XFS_ERRLEVEL_OFF:       0
> -		XFS_ERRLEVEL_LOW:       1
> -		XFS_ERRLEVEL_HIGH:      5
> -
> -  fs.xfs.panic_mask		(Min: 0  Default: 0  Max: 256)
> -	Causes certain error conditions to call BUG(). Value is a bitmask;
> -	OR together the tags which represent errors which should cause panics:
> -
> -		XFS_NO_PTAG                     0
> -		XFS_PTAG_IFLUSH                 0x00000001
> -		XFS_PTAG_LOGRES                 0x00000002
> -		XFS_PTAG_AILDELETE              0x00000004
> -		XFS_PTAG_ERROR_REPORT           0x00000008
> -		XFS_PTAG_SHUTDOWN_CORRUPT       0x00000010
> -		XFS_PTAG_SHUTDOWN_IOERROR       0x00000020
> -		XFS_PTAG_SHUTDOWN_LOGERROR      0x00000040
> -		XFS_PTAG_FSBLOCK_ZERO           0x00000080
> -		XFS_PTAG_VERIFIER_ERROR         0x00000100
> -
> -	This option is intended for debugging only.
> -
> -  fs.xfs.irix_symlink_mode	(Min: 0  Default: 0  Max: 1)
> -	Controls whether symlinks are created with mode 0777 (default)
> -	or whether their mode is affected by the umask (irix mode).
> -
> -  fs.xfs.irix_sgid_inherit	(Min: 0  Default: 0  Max: 1)
> -	Controls files created in SGID directories.
> -	If the group ID of the new file does not match the effective group
> -	ID or one of the supplementary group IDs of the parent dir, the
> -	ISGID bit is cleared if the irix_sgid_inherit compatibility sysctl
> -	is set.
> -
> -  fs.xfs.inherit_sync		(Min: 0  Default: 1  Max: 1)
> -	Setting this to "1" will cause the "sync" flag set
> -	by the xfs_io(8) chattr command on a directory to be
> -	inherited by files in that directory.
> -
> -  fs.xfs.inherit_nodump		(Min: 0  Default: 1  Max: 1)
> -	Setting this to "1" will cause the "nodump" flag set
> -	by the xfs_io(8) chattr command on a directory to be
> -	inherited by files in that directory.
> -
> -  fs.xfs.inherit_noatime	(Min: 0  Default: 1  Max: 1)
> -	Setting this to "1" will cause the "noatime" flag set
> -	by the xfs_io(8) chattr command on a directory to be
> -	inherited by files in that directory.
> -
> -  fs.xfs.inherit_nosymlinks	(Min: 0  Default: 1  Max: 1)
> -	Setting this to "1" will cause the "nosymlinks" flag set
> -	by the xfs_io(8) chattr command on a directory to be
> -	inherited by files in that directory.
> -
> -  fs.xfs.inherit_nodefrag	(Min: 0  Default: 1  Max: 1)
> -	Setting this to "1" will cause the "nodefrag" flag set
> -	by the xfs_io(8) chattr command on a directory to be
> -	inherited by files in that directory.
> -
> -  fs.xfs.rotorstep		(Min: 1  Default: 1  Max: 256)
> -	In "inode32" allocation mode, this option determines how many
> -	files the allocator attempts to allocate in the same allocation
> -	group before moving to the next allocation group.  The intent
> -	is to control the rate at which the allocator moves between
> -	allocation groups when allocating extents for new files.
> -
> -Deprecated Sysctls
> -==================
> -
> -None at present.
> -
> -
> -Removed Sysctls
> -===============
> -
> -  Name				Removed
> -  ----				-------
> -  fs.xfs.xfsbufd_centisec	v4.0
> -  fs.xfs.age_buffer_centisecs	v4.0
> -
> -
> -Error handling
> -==============
> -
> -XFS can act differently according to the type of error found during its
> -operation. The implementation introduces the following concepts to the error
> -handler:
> -
> - -failure speed:
> -	Defines how fast XFS should propagate an error upwards when a specific
> -	error is found during the filesystem operation. It can propagate
> -	immediately, after a defined number of retries, after a set time period,
> -	or simply retry forever.
> -
> - -error classes:
> -	Specifies the subsystem the error configuration will apply to, such as
> -	metadata IO or memory allocation. Different subsystems will have
> -	different error handlers for which behaviour can be configured.
> -
> - -error handlers:
> -	Defines the behavior for a specific error.
> -
> -The filesystem behavior during an error can be set via sysfs files. Each
> -error handler works independently - the first condition met by an error handler
> -for a specific class will cause the error to be propagated rather than reset and
> -retried.
> -
> -The action taken by the filesystem when the error is propagated is context
> -dependent - it may cause a shut down in the case of an unrecoverable error,
> -it may be reported back to userspace, or it may even be ignored because
> -there's nothing useful we can with the error or anyone we can report it to (e.g.
> -during unmount).
> -
> -The configuration files are organized into the following hierarchy for each
> -mounted filesystem:
> -
> -  /sys/fs/xfs/<dev>/error/<class>/<error>/
> -
> -Where:
> -  <dev>
> -	The short device name of the mounted filesystem. This is the same device
> -	name that shows up in XFS kernel error messages as "XFS(<dev>): ..."
> -
> -  <class>
> -	The subsystem the error configuration belongs to. As of 4.9, the defined
> -	classes are:
> -
> -		- "metadata": applies metadata buffer write IO
> -
> -  <error>
> -	The individual error handler configurations.
> -
> -
> -Each filesystem has "global" error configuration options defined in their top
> -level directory:
> -
> -  /sys/fs/xfs/<dev>/error/
> -
> -  fail_at_unmount		(Min:  0  Default:  1  Max: 1)
> -	Defines the filesystem error behavior at unmount time.
> -
> -	If set to a value of 1, XFS will override all other error configurations
> -	during unmount and replace them with "immediate fail" characteristics.
> -	i.e. no retries, no retry timeout. This will always allow unmount to
> -	succeed when there are persistent errors present.
> -
> -	If set to 0, the configured retry behaviour will continue until all
> -	retries and/or timeouts have been exhausted. This will delay unmount
> -	completion when there are persistent errors, and it may prevent the
> -	filesystem from ever unmounting fully in the case of "retry forever"
> -	handler configurations.
> -
> -	Note: there is no guarantee that fail_at_unmount can be set while an
> -	unmount is in progress. It is possible that the sysfs entries are
> -	removed by the unmounting filesystem before a "retry forever" error
> -	handler configuration causes unmount to hang, and hence the filesystem
> -	must be configured appropriately before unmount begins to prevent
> -	unmount hangs.
> -
> -Each filesystem has specific error class handlers that define the error
> -propagation behaviour for specific errors. There is also a "default" error
> -handler defined, which defines the behaviour for all errors that don't have
> -specific handlers defined. Where multiple retry constraints are configuredi for
> -a single error, the first retry configuration that expires will cause the error
> -to be propagated. The handler configurations are found in the directory:
> -
> -  /sys/fs/xfs/<dev>/error/<class>/<error>/
> -
> -  max_retries			(Min: -1  Default: Varies  Max: INTMAX)
> -	Defines the allowed number of retries of a specific error before
> -	the filesystem will propagate the error. The retry count for a given
> -	error context (e.g. a specific metadata buffer) is reset every time
> -	there is a successful completion of the operation.
> -
> -	Setting the value to "-1" will cause XFS to retry forever for this
> -	specific error.
> -
> -	Setting the value to "0" will cause XFS to fail immediately when the
> -	specific error is reported.
> -
> -	Setting the value to "N" (where 0 < N < Max) will make XFS retry the
> -	operation "N" times before propagating the error.
> -
> -  retry_timeout_seconds		(Min:  -1  Default:  Varies  Max: 1 day)
> -	Define the amount of time (in seconds) that the filesystem is
> -	allowed to retry its operations when the specific error is
> -	found.
> -
> -	Setting the value to "-1" will allow XFS to retry forever for this
> -	specific error.
> -
> -	Setting the value to "0" will cause XFS to fail immediately when the
> -	specific error is reported.
> -
> -	Setting the value to "N" (where 0 < N < Max) will allow XFS to retry the
> -	operation for up to "N" seconds before propagating the error.
> -
> -Note: The default behaviour for a specific error handler is dependent on both
> -the class and error context. For example, the default values for
> -"metadata/ENODEV" are "0" rather than "-1" so that this error handler defaults
> -to "fail immediately" behaviour. This is done because ENODEV is a fatal,
> -unrecoverable error no matter how many times the metadata IO is retried.
> diff --git a/MAINTAINERS b/MAINTAINERS
> index d0ed73599..66e972e9a 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -17364,7 +17364,7 @@ L:	linux-xfs@vger.kernel.org
>  W:	http://xfs.org/
>  T:	git git://git.kernel.org/pub/scm/fs/xfs/xfs-linux.git
>  S:	Supported
> -F:	Documentation/filesystems/xfs.txt
> +F:	Documentation/filesystems/xfs.rst
>  F:	fs/xfs/
>  
>  XILINX AXI ETHERNET DRIVER
> -- 
> 2.22.0
>

Patch
diff mbox series

diff --git a/Documentation/filesystems/dax.txt b/Documentation/filesystems/dax.txt
index 6d2c0d340..c333285b8 100644
--- a/Documentation/filesystems/dax.txt
+++ b/Documentation/filesystems/dax.txt
@@ -76,7 +76,7 @@  exposure of uninitialized data through mmap.
 These filesystems may be used for inspiration:
 - ext2: see Documentation/filesystems/ext2.txt
 - ext4: see Documentation/filesystems/ext4/
-- xfs:  see Documentation/filesystems/xfs.txt
+- xfs:  see Documentation/filesystems/xfs.rst
 
 
 Handling Media Errors
diff --git a/Documentation/filesystems/index.rst b/Documentation/filesystems/index.rst
index 1131c34d7..a4cf5fca4 100644
--- a/Documentation/filesystems/index.rst
+++ b/Documentation/filesystems/index.rst
@@ -16,7 +16,7 @@  algorithms work.
 .. toctree::
    :maxdepth: 2
 
-   path-lookup.rst
+   path-lookup
    api-summary
    splice
 
@@ -40,4 +40,5 @@  Documentation for individual filesystem types can be found here.
 .. toctree::
    :maxdepth: 2
 
-   binderfs.rst
+   binderfs
+   xfs
diff --git a/Documentation/filesystems/xfs.rst b/Documentation/filesystems/xfs.rst
new file mode 100644
index 000000000..d36ef042c
--- /dev/null
+++ b/Documentation/filesystems/xfs.rst
@@ -0,0 +1,468 @@ 
+.. SPDX-License-Identifier: GPL-2.0
+======================
+The SGI XFS Filesystem
+======================
+
+XFS is a high performance journaling filesystem which originated
+on the SGI IRIX platform.  It is completely multi-threaded, can
+support large files and large filesystems, extended attributes,
+variable block sizes, is extent based, and makes extensive use of
+Btrees (directories, extents, free space) to aid both performance
+and scalability.
+
+Refer to the documentation at https://xfs.wiki.kernel.org/
+for further details.  This implementation is on-disk compatible
+with the IRIX version of XFS.
+
+
+Mount Options
+=============
+
+When mounting an XFS filesystem, the following options are accepted.  For
+boolean mount options, the names with the "(*)" prefix is the default behaviour.
+For example, take a behaviour enabled by default to be a one (1) or, a zero (0)
+otherwise, ``(*)[no]default`` would be 0 while ``[no](*)default`` , a 1.
+
+   allocsize=<size>
+        Sets the buffered I/O end-of-file preallocation size when doing delayed
+        allocation writeout (default size is 64KiB).  Valid values for this
+        option are page size (typically 4KiB) through to 1GiB, inclusive, in
+        power-of-2 increments.
+
+        The default behaviour is for dynamic end-of-file preallocation size,
+        which uses a set of heuristics to optimise the preallocation size based
+        on the current allocation patterns within the file and the access
+        patterns to the file. Specifying a fixed allocsize value turns off the
+        dynamic behaviour.
+
+   [no]attr2
+        The options enable/disable an "opportunistic" improvement to be made in
+        the way inline extended attributes are stored on-disk.  When the new
+        form is used for the first time when ``attr2`` is selected (either when
+        setting or removing extended attributes) the on-disk superblock feature
+        bit field will be updated to reflect this format being in use.
+
+        The default behaviour is determined by the on-disk feature bit
+        indicating that ``attr2`` behaviour is active. If either mount option is
+        set, then that becomes the new default used by the filesystem. However
+        on CRC enabled filesystems, the ``attr2`` format is always used , and so
+        will reject the ``noattr2`` mount option if it is set.
+
+   (*)[no]discard
+        Enable/disable the issuing of commands to let the block device reclaim
+        space freed by the filesystem.  This is useful for SSD devices, thinly
+        provisioned LUNs and virtual machine images, but may have a performance
+        impact.
+
+        Note: It is currently recommended that you use the ``fstrim``
+        application to discard unused blocks rather than the ``discard`` mount
+        option because the performance impact of this option is quite severe.
+
+   grpid/bsdgroups
+   nogrpid/(*)sysvgroups
+        These options define what group ID a newly created file gets.  When
+        ``grpid`` is set, it takes the group ID of the directory in which it is
+        created; otherwise it takes the ``fsgid`` of the current process, unless
+        the directory has the ``setgid`` bit set, in which case it takes the
+        ``gid`` from the parent directory, and also gets the ``setgid`` bit set
+        if it is a directory itself.
+
+   filestreams
+        Make the data allocator use the filestreams allocation mode across the
+        entire filesystem rather than just on directories configured to use it.
+
+   (*)[no]ikeep
+        When ``ikeep`` is specified, XFS does not delete empty inode clusters
+        and keeps them around on disk.  When ``noikeep`` is specified, empty
+        inode clusters are returned to the free space pool.
+
+   inode32 | (*)inode64
+        When ``inode32`` is specified, it indicates that XFS limits inode
+        creation to locations which will not result in inode numbers with more
+        than 32 bits of significance.
+
+        When ``inode64`` is specified, it indicates that XFS is allowed to
+        create inodes at any location in the filesystem, including those which
+        will result in inode numbers occupying more than 32 bits of
+        significance.
+
+        ``inode32`` is provided for backwards compatibility with older systems
+        and applications, since 64 bits inode numbers might cause problems for
+        some applications that cannot handle large inode numbers.  If
+        applications are in use which do not handle inode numbers bigger than 32
+        bits, the ``inode32`` option should be specified.
+
+
+   (*)[no]largeio
+        If ``nolargeio`` is specified, the optimal I/O reported in st_blksize by
+        **stat(2)** will be as small as possible to allow user applications to
+        avoid inefficient read/modify/write I/O.  This is typically the page
+        size of the machine, as this is the granularity of the page cache.
+
+        If ``largeio`` is specified, a filesystem that was created with a
+        ``swidth`` specified will return the ``swidth`` value (in bytes) in
+        st_blksize. If the filesystem does not have a ``swidth`` specified but
+        does specify an ``allocsize`` then ``allocsize`` (in bytes) will be
+        returned instead. Otherwise the behaviour is the same as if
+        ``nolargeio`` was specified.
+
+   logbufs=<value>
+        Set the number of in-memory log buffers to ``value``.  Valid numbers
+        range from 2-8 inclusive.
+
+        The default value is 8 buffers.
+
+        If the memory cost of 8 log buffers is too high on small systems, then
+        it may be reduced at some cost to performance on metadata intensive
+        workloads. The ``logbsize`` option below controls the size of each
+        buffer and so is also relevant to this case.
+
+   logbsize=<value>
+        Set the size of each in-memory log buffer to ``value``.  The size may be
+        specified in bytes, or in kilobytes with a "k" suffix. Valid sizes for
+        version 1 and version 2 logs are 16384 (16k) and 32768 (32k).  Valid
+        sizes for version 2 logs also include 65536 (64k), 131072 (128k) and
+        262144 (256k). The ``logbsize`` must be an integer multiple of the
+        "log stripe unit" configured at mkfs time.
+
+        The default value for for version 1 logs is 32768, while the default
+        value for version 2 logs is ``MAX(32768, log_sunit)``.
+
+   logdev=<device>
+        Use ``device`` as an external log (metadata journal).  In an XFS
+        filesystem, the log device can be separate from the data device or
+        contained within it.
+
+   rtdev=<device>
+        An XFS filesystem has up to three parts: a data section, a log section,
+        and a real-time section.  The real-time section is optional.  If
+        enabled, ``rtdev`` sets ``device`` to be used as an external real-time
+        section, similar to ``logdev`` above.
+
+   noalign
+        Data allocations will not be aligned at stripe unit boundaries. This is
+        only relevant to filesystems created with non-zero data alignment
+        parameters (sunit, swidth) by mkfs.
+
+   norecovery
+        The filesystem will be mounted without running log recovery.  If the
+        filesystem was not cleanly unmounted, it is likely to be inconsistent
+        when mounted in ``norecovery`` mode.  Some files or directories may not
+        be accessible because of this.  Filesystems mounted ``norecovery`` must
+        be mounted read-only or the mount will fail.
+
+   nouuid
+        Don't check for double mounted file systems using the file system uuid.
+        This is useful to mount LVM snapshot volumes, and often used in
+        combination with ``norecovery`` for mounting read-only snapshots.
+
+   noquota
+	Forcibly turns off all quota accounting and enforcement
+	within the filesystem.
+
+   uquota/usrquota/uqnoenforce/quota
+        User disk quota accounting enabled, and limits (optionally) enforced.
+        Refer to **xfs_quota(8)** for further details.
+
+   gquota/grpquota/gqnoenforce
+        Group disk quota accounting enabled and limits (optionally) enforced.
+        Refer to **xfs_quota(8)** for further details.
+
+   pquota/prjquota/pqnoenforce
+        Project disk quota accounting enabled and limits (optionally) enforced.
+        Refer to **xfs_quota(8)** for further details.
+
+   sunit=<value>
+        Used to specify the stripe unit for a RAID device or (in conjunction
+        with ``swidth`` below) a stripe volume.  ``value`` must be specified in
+        512-byte block units. This option is only relevant to filesystems that
+        were created with non-zero data alignment parameters.
+
+        The ``sunit`` parameter specified must be compatible with the existing
+        filesystem alignment characteristics.  In general, that means the only
+        valid changes to ``sunit`` are increasing it by a power-of-2 multiple.
+
+        Typically, this mount option is necessary only after an underlying RAID
+        device has had its geometry modified, such as adding a new disk to a
+        RAID5 lun and reshaping it.
+
+   swidth=<value>
+        Used to specify the stripe width for a RAID device or (in conjunction
+        with ``sunit`` above) a stripe volume.  ``value`` must be specified in
+        512-byte block units. This option, like ``sunit`` above, is only
+        relevant to filesystems that were created with non-zero data alignment
+        parameters.
+
+        The ``swidth`` parameter specified must be compatible with the existing
+        filesystem alignment characteristics.  In general, that means the only
+        valid swidth values are any integer multiple of a valid ``sunit`` value.
+
+        Typically, this mount option is necessary only after an underlying RAID
+        device has had its geometry modified, such as adding a new disk to a
+        RAID5 lun and reshaping it.
+
+
+   swalloc
+        Data allocations will be rounded up to stripe width boundaries when the
+        current end of file is being extended and the file size is larger than
+        the stripe width size.
+
+   wsync
+        When specified, all filesystem namespace operations are executed
+        synchronously. This ensures that when the namespace operation (create,
+        unlink, etc) completes, the change to the namespace is on stable
+        storage. This is useful in HA setups where failover must not result in
+        clients seeing inconsistent namespace presentation during or after a
+        failover event.
+
+
+Deprecated Mount Options
+========================
+
+  Name				Removal Schedule
+  ----				----------------
+
+
+Removed Mount Options
+=====================
+
+  Name				Removed
+  ----				-------
+  delaylog/nodelaylog		v4.0
+  ihashsize			v4.0
+  irixsgid			v4.0
+  osyncisdsync/osyncisosync	v4.0
+  barrier			v4.19
+  nobarrier			v4.19
+
+
+sysctls
+=======
+
+The following sysctls are available for the XFS filesystem:
+
+  fs.xfs.stats_clear		(Min: 0  Default: 0  Max: 1)
+	Setting this to "1" clears accumulated XFS statistics
+	in /proc/fs/xfs/stat.  It then immediately resets to "0".
+
+  fs.xfs.xfssyncd_centisecs	(Min: 100  Default: 3000  Max: 720000)
+	The interval at which the filesystem flushes metadata
+	out to disk and runs internal cache cleanup routines.
+
+  fs.xfs.filestream_centisecs	(Min: 1  Default: 3000  Max: 360000)
+	The interval at which the filesystem ages filestreams cache
+	references and returns timed-out AGs back to the free stream
+	pool.
+
+  fs.xfs.speculative_prealloc_lifetime
+		(Units: seconds   Min: 1  Default: 300  Max: 86400)
+	The interval at which the background scanning for inodes
+	with unused speculative preallocation runs. The scan
+	removes unused preallocation from clean inodes and releases
+	the unused space back to the free pool.
+
+  fs.xfs.error_level		(Min: 0  Default: 3  Max: 11)
+	A volume knob for error reporting when internal errors occur.
+	This will generate detailed messages & backtraces for filesystem
+	shutdowns, for example.  Current threshold values are:
+
+		XFS_ERRLEVEL_OFF:       0
+		XFS_ERRLEVEL_LOW:       1
+		XFS_ERRLEVEL_HIGH:      5
+
+  fs.xfs.panic_mask		(Min: 0  Default: 0  Max: 256)
+	Causes certain error conditions to call BUG(). Value is a bitmask;
+	OR together the tags which represent errors which should cause panics:
+
+		XFS_NO_PTAG                     0
+		XFS_PTAG_IFLUSH                 0x00000001
+		XFS_PTAG_LOGRES                 0x00000002
+		XFS_PTAG_AILDELETE              0x00000004
+		XFS_PTAG_ERROR_REPORT           0x00000008
+		XFS_PTAG_SHUTDOWN_CORRUPT       0x00000010
+		XFS_PTAG_SHUTDOWN_IOERROR       0x00000020
+		XFS_PTAG_SHUTDOWN_LOGERROR      0x00000040
+		XFS_PTAG_FSBLOCK_ZERO           0x00000080
+		XFS_PTAG_VERIFIER_ERROR         0x00000100
+
+	This option is intended for debugging only.
+
+  fs.xfs.irix_symlink_mode	(Min: 0  Default: 0  Max: 1)
+	Controls whether symlinks are created with mode 0777 (default)
+	or whether their mode is affected by the umask (irix mode).
+
+  fs.xfs.irix_sgid_inherit	(Min: 0  Default: 0  Max: 1)
+	Controls files created in SGID directories.
+	If the group ID of the new file does not match the effective group
+	ID or one of the supplementary group IDs of the parent dir, the
+	ISGID bit is cleared if the irix_sgid_inherit compatibility sysctl
+	is set.
+
+  fs.xfs.inherit_sync		(Min: 0  Default: 1  Max: 1)
+	Setting this to "1" will cause the "sync" flag set
+	by the **xfs_io(8)** chattr command on a directory to be
+	inherited by files in that directory.
+
+  fs.xfs.inherit_nodump		(Min: 0  Default: 1  Max: 1)
+	Setting this to "1" will cause the "nodump" flag set
+	by the **xfs_io(8)** chattr command on a directory to be
+	inherited by files in that directory.
+
+  fs.xfs.inherit_noatime	(Min: 0  Default: 1  Max: 1)
+	Setting this to "1" will cause the "noatime" flag set
+	by the **xfs_io(8)** chattr command on a directory to be
+	inherited by files in that directory.
+
+  fs.xfs.inherit_nosymlinks	(Min: 0  Default: 1  Max: 1)
+	Setting this to "1" will cause the "nosymlinks" flag set
+	by the **xfs_io(8)** chattr command on a directory to be
+	inherited by files in that directory.
+
+  fs.xfs.inherit_nodefrag	(Min: 0  Default: 1  Max: 1)
+	Setting this to "1" will cause the "nodefrag" flag set
+	by the **xfs_io(8)** chattr command on a directory to be
+	inherited by files in that directory.
+
+  fs.xfs.rotorstep		(Min: 1  Default: 1  Max: 256)
+	In "inode32" allocation mode, this option determines how many
+	files the allocator attempts to allocate in the same allocation
+	group before moving to the next allocation group.  The intent
+	is to control the rate at which the allocator moves between
+	allocation groups when allocating extents for new files.
+
+Deprecated Sysctls
+==================
+
+None at present.
+
+
+Removed Sysctls
+===============
+
+  Name				Removed
+  ----				-------
+  fs.xfs.xfsbufd_centisec	v4.0
+  fs.xfs.age_buffer_centisecs	v4.0
+
+
+Error handling
+==============
+
+XFS can act differently according to the type of error found during its
+operation. The implementation introduces the following concepts to the error
+handler:
+
+ -failure speed:
+	Defines how fast XFS should propagate an error upwards when a specific
+	error is found during the filesystem operation. It can propagate
+	immediately, after a defined number of retries, after a set time period,
+	or simply retry forever.
+
+ -error classes:
+	Specifies the subsystem the error configuration will apply to, such as
+	metadata IO or memory allocation. Different subsystems will have
+	different error handlers for which behaviour can be configured.
+
+ -error handlers:
+	Defines the behavior for a specific error.
+
+The filesystem behavior during an error can be set via sysfs files. Each
+error handler works independently - the first condition met by an error handler
+for a specific class will cause the error to be propagated rather than reset and
+retried.
+
+The action taken by the filesystem when the error is propagated is context
+dependent - it may cause a shut down in the case of an unrecoverable error,
+it may be reported back to userspace, or it may even be ignored because
+there's nothing useful we can with the error or anyone we can report it to (e.g.
+during unmount).
+
+The configuration files are organized into the following hierarchy for each
+mounted filesystem:
+
+  /sys/fs/xfs/<dev>/error/<class>/<error>/
+
+Where:
+  <dev>
+	The short device name of the mounted filesystem. This is the same device
+	name that shows up in XFS kernel error messages as "XFS(<dev>): ..."
+
+  <class>
+	The subsystem the error configuration belongs to. As of 4.9, the defined
+	classes are:
+
+		- "metadata": applies metadata buffer write IO
+
+  <error>
+	The individual error handler configurations.
+
+
+Each filesystem has "global" error configuration options defined in their top
+level directory:
+
+  /sys/fs/xfs/<dev>/error/
+
+  fail_at_unmount		(Min:  0  Default:  1  Max: 1)
+	Defines the filesystem error behavior at unmount time.
+
+	If set to a value of 1, XFS will override all other error configurations
+	during unmount and replace them with "immediate fail" characteristics.
+	i.e. no retries, no retry timeout. This will always allow unmount to
+	succeed when there are persistent errors present.
+
+	If set to 0, the configured retry behaviour will continue until all
+	retries and/or timeouts have been exhausted. This will delay unmount
+	completion when there are persistent errors, and it may prevent the
+	filesystem from ever unmounting fully in the case of "retry forever"
+	handler configurations.
+
+	Note: there is no guarantee that fail_at_unmount can be set while an
+	unmount is in progress. It is possible that the sysfs entries are
+	removed by the unmounting filesystem before a "retry forever" error
+	handler configuration causes unmount to hang, and hence the filesystem
+	must be configured appropriately before unmount begins to prevent
+	unmount hangs.
+
+Each filesystem has specific error class handlers that define the error
+propagation behaviour for specific errors. There is also a "default" error
+handler defined, which defines the behaviour for all errors that don't have
+specific handlers defined. Where multiple retry constraints are configuredi for
+a single error, the first retry configuration that expires will cause the error
+to be propagated. The handler configurations are found in the directory:
+
+  /sys/fs/xfs/<dev>/error/<class>/<error>/
+
+  max_retries			(Min: -1  Default: Varies  Max: INTMAX)
+	Defines the allowed number of retries of a specific error before
+	the filesystem will propagate the error. The retry count for a given
+	error context (e.g. a specific metadata buffer) is reset every time
+	there is a successful completion of the operation.
+
+	Setting the value to "-1" will cause XFS to retry forever for this
+	specific error.
+
+	Setting the value to "0" will cause XFS to fail immediately when the
+	specific error is reported.
+
+	Setting the value to "N" (where 0 < N < Max) will make XFS retry the
+	operation "N" times before propagating the error.
+
+  retry_timeout_seconds		(Min:  -1  Default:  Varies  Max: 1 day)
+	Define the amount of time (in seconds) that the filesystem is
+	allowed to retry its operations when the specific error is
+	found.
+
+	Setting the value to "-1" will allow XFS to retry forever for this
+	specific error.
+
+	Setting the value to "0" will cause XFS to fail immediately when the
+	specific error is reported.
+
+	Setting the value to "N" (where 0 < N < Max) will allow XFS to retry the
+	operation for up to "N" seconds before propagating the error.
+
+Note: The default behaviour for a specific error handler is dependent on both
+the class and error context. For example, the default values for
+"metadata/ENODEV" are "0" rather than "-1" so that this error handler defaults
+to "fail immediately" behaviour. This is done because ENODEV is a fatal,
+unrecoverable error no matter how many times the metadata IO is retried.
diff --git a/Documentation/filesystems/xfs.txt b/Documentation/filesystems/xfs.txt
deleted file mode 100644
index a5cbb5e0e..000000000
--- a/Documentation/filesystems/xfs.txt
+++ /dev/null
@@ -1,470 +0,0 @@ 
-
-The SGI XFS Filesystem
-======================
-
-XFS is a high performance journaling filesystem which originated
-on the SGI IRIX platform.  It is completely multi-threaded, can
-support large files and large filesystems, extended attributes,
-variable block sizes, is extent based, and makes extensive use of
-Btrees (directories, extents, free space) to aid both performance
-and scalability.
-
-Refer to the documentation at https://xfs.wiki.kernel.org/
-for further details.  This implementation is on-disk compatible
-with the IRIX version of XFS.
-
-
-Mount Options
-=============
-
-When mounting an XFS filesystem, the following options are accepted.
-For boolean mount options, the names with the (*) suffix is the
-default behaviour.
-
-  allocsize=size
-	Sets the buffered I/O end-of-file preallocation size when
-	doing delayed allocation writeout (default size is 64KiB).
-	Valid values for this option are page size (typically 4KiB)
-	through to 1GiB, inclusive, in power-of-2 increments.
-
-	The default behaviour is for dynamic end-of-file
-	preallocation size, which uses a set of heuristics to
-	optimise the preallocation size based on the current
-	allocation patterns within the file and the access patterns
-	to the file. Specifying a fixed allocsize value turns off
-	the dynamic behaviour.
-
-  attr2
-  noattr2
-	The options enable/disable an "opportunistic" improvement to
-	be made in the way inline extended attributes are stored
-	on-disk.  When the new form is used for the first time when
-	attr2 is selected (either when setting or removing extended
-	attributes) the on-disk superblock feature bit field will be
-	updated to reflect this format being in use.
-
-	The default behaviour is determined by the on-disk feature
-	bit indicating that attr2 behaviour is active. If either
-	mount option it set, then that becomes the new default used
-	by the filesystem.
-
-	CRC enabled filesystems always use the attr2 format, and so
-	will reject the noattr2 mount option if it is set.
-
-  discard
-  nodiscard (*)
-	Enable/disable the issuing of commands to let the block
-	device reclaim space freed by the filesystem.  This is
-	useful for SSD devices, thinly provisioned LUNs and virtual
-	machine images, but may have a performance impact.
-
-	Note: It is currently recommended that you use the fstrim
-	application to discard unused blocks rather than the discard
-	mount option because the performance impact of this option
-	is quite severe.
-
-  grpid/bsdgroups
-  nogrpid/sysvgroups (*)
-	These options define what group ID a newly created file
-	gets.  When grpid is set, it takes the group ID of the
-	directory in which it is created; otherwise it takes the
-	fsgid of the current process, unless the directory has the
-	setgid bit set, in which case it takes the gid from the
-	parent directory, and also gets the setgid bit set if it is
-	a directory itself.
-
-  filestreams
-	Make the data allocator use the filestreams allocation mode
-	across the entire filesystem rather than just on directories
-	configured to use it.
-
-  ikeep
-  noikeep (*)
-	When ikeep is specified, XFS does not delete empty inode
-	clusters and keeps them around on disk.  When noikeep is
-	specified, empty inode clusters are returned to the free
-	space pool.
-
-  inode32
-  inode64 (*)
-	When inode32 is specified, it indicates that XFS limits
-	inode creation to locations which will not result in inode
-	numbers with more than 32 bits of significance.
-
-	When inode64 is specified, it indicates that XFS is allowed
-	to create inodes at any location in the filesystem,
-	including those which will result in inode numbers occupying
-	more than 32 bits of significance. 
-
-	inode32 is provided for backwards compatibility with older
-	systems and applications, since 64 bits inode numbers might
-	cause problems for some applications that cannot handle
-	large inode numbers.  If applications are in use which do
-	not handle inode numbers bigger than 32 bits, the inode32
-	option should be specified.
-
-
-  largeio
-  nolargeio (*)
-	If "nolargeio" is specified, the optimal I/O reported in
-	st_blksize by stat(2) will be as small as possible to allow
-	user applications to avoid inefficient read/modify/write
-	I/O.  This is typically the page size of the machine, as
-	this is the granularity of the page cache.
-
-	If "largeio" specified, a filesystem that was created with a
-	"swidth" specified will return the "swidth" value (in bytes)
-	in st_blksize. If the filesystem does not have a "swidth"
-	specified but does specify an "allocsize" then "allocsize"
-	(in bytes) will be returned instead. Otherwise the behaviour
-	is the same as if "nolargeio" was specified.
-
-  logbufs=value
-	Set the number of in-memory log buffers.  Valid numbers
-	range from 2-8 inclusive.
-
-	The default value is 8 buffers.
-
-	If the memory cost of 8 log buffers is too high on small
-	systems, then it may be reduced at some cost to performance
-	on metadata intensive workloads. The logbsize option below
-	controls the size of each buffer and so is also relevant to
-	this case.
-
-  logbsize=value
-	Set the size of each in-memory log buffer.  The size may be
-	specified in bytes, or in kilobytes with a "k" suffix.
-	Valid sizes for version 1 and version 2 logs are 16384 (16k)
-	and 32768 (32k).  Valid sizes for version 2 logs also
-	include 65536 (64k), 131072 (128k) and 262144 (256k). The
-	logbsize must be an integer multiple of the log
-	stripe unit configured at mkfs time.
-
-	The default value for for version 1 logs is 32768, while the
-	default value for version 2 logs is MAX(32768, log_sunit).
-
-  logdev=device and rtdev=device
-	Use an external log (metadata journal) and/or real-time device.
-	An XFS filesystem has up to three parts: a data section, a log
-	section, and a real-time section.  The real-time section is
-	optional, and the log section can be separate from the data
-	section or contained within it.
-
-  noalign
-	Data allocations will not be aligned at stripe unit
-	boundaries. This is only relevant to filesystems created
-	with non-zero data alignment parameters (sunit, swidth) by
-	mkfs.
-
-  norecovery
-	The filesystem will be mounted without running log recovery.
-	If the filesystem was not cleanly unmounted, it is likely to
-	be inconsistent when mounted in "norecovery" mode.
-	Some files or directories may not be accessible because of this.
-	Filesystems mounted "norecovery" must be mounted read-only or
-	the mount will fail.
-
-  nouuid
-	Don't check for double mounted file systems using the file
-	system uuid.  This is useful to mount LVM snapshot volumes,
-	and often used in combination with "norecovery" for mounting
-	read-only snapshots.
-
-  noquota
-	Forcibly turns off all quota accounting and enforcement
-	within the filesystem.
-
-  uquota/usrquota/uqnoenforce/quota
-	User disk quota accounting enabled, and limits (optionally)
-	enforced.  Refer to xfs_quota(8) for further details.
-
-  gquota/grpquota/gqnoenforce
-	Group disk quota accounting enabled and limits (optionally)
-	enforced.  Refer to xfs_quota(8) for further details.
-
-  pquota/prjquota/pqnoenforce
-	Project disk quota accounting enabled and limits (optionally)
-	enforced.  Refer to xfs_quota(8) for further details.
-
-  sunit=value and swidth=value
-	Used to specify the stripe unit and width for a RAID device
-	or a stripe volume.  "value" must be specified in 512-byte
-	block units. These options are only relevant to filesystems
-	that were created with non-zero data alignment parameters.
-
-	The sunit and swidth parameters specified must be compatible
-	with the existing filesystem alignment characteristics.  In
-	general, that means the only valid changes to sunit are
-	increasing it by a power-of-2 multiple. Valid swidth values
-	are any integer multiple of a valid sunit value.
-
-	Typically the only time these mount options are necessary if
-	after an underlying RAID device has had it's geometry
-	modified, such as adding a new disk to a RAID5 lun and
-	reshaping it.
-
-  swalloc
-	Data allocations will be rounded up to stripe width boundaries
-	when the current end of file is being extended and the file
-	size is larger than the stripe width size.
-
-  wsync
-	When specified, all filesystem namespace operations are
-	executed synchronously. This ensures that when the namespace
-	operation (create, unlink, etc) completes, the change to the
-	namespace is on stable storage. This is useful in HA setups
-	where failover must not result in clients seeing
-	inconsistent namespace presentation during or after a
-	failover event.
-
-
-Deprecated Mount Options
-========================
-
-  Name				Removal Schedule
-  ----				----------------
-
-
-Removed Mount Options
-=====================
-
-  Name				Removed
-  ----				-------
-  delaylog/nodelaylog		v4.0
-  ihashsize			v4.0
-  irixsgid			v4.0
-  osyncisdsync/osyncisosync	v4.0
-  barrier			v4.19
-  nobarrier			v4.19
-
-
-sysctls
-=======
-
-The following sysctls are available for the XFS filesystem:
-
-  fs.xfs.stats_clear		(Min: 0  Default: 0  Max: 1)
-	Setting this to "1" clears accumulated XFS statistics
-	in /proc/fs/xfs/stat.  It then immediately resets to "0".
-
-  fs.xfs.xfssyncd_centisecs	(Min: 100  Default: 3000  Max: 720000)
-	The interval at which the filesystem flushes metadata
-	out to disk and runs internal cache cleanup routines.
-
-  fs.xfs.filestream_centisecs	(Min: 1  Default: 3000  Max: 360000)
-	The interval at which the filesystem ages filestreams cache
-	references and returns timed-out AGs back to the free stream
-	pool.
-
-  fs.xfs.speculative_prealloc_lifetime
-		(Units: seconds   Min: 1  Default: 300  Max: 86400)
-	The interval at which the background scanning for inodes
-	with unused speculative preallocation runs. The scan
-	removes unused preallocation from clean inodes and releases
-	the unused space back to the free pool.
-
-  fs.xfs.error_level		(Min: 0  Default: 3  Max: 11)
-	A volume knob for error reporting when internal errors occur.
-	This will generate detailed messages & backtraces for filesystem
-	shutdowns, for example.  Current threshold values are:
-
-		XFS_ERRLEVEL_OFF:       0
-		XFS_ERRLEVEL_LOW:       1
-		XFS_ERRLEVEL_HIGH:      5
-
-  fs.xfs.panic_mask		(Min: 0  Default: 0  Max: 256)
-	Causes certain error conditions to call BUG(). Value is a bitmask;
-	OR together the tags which represent errors which should cause panics:
-
-		XFS_NO_PTAG                     0
-		XFS_PTAG_IFLUSH                 0x00000001
-		XFS_PTAG_LOGRES                 0x00000002
-		XFS_PTAG_AILDELETE              0x00000004
-		XFS_PTAG_ERROR_REPORT           0x00000008
-		XFS_PTAG_SHUTDOWN_CORRUPT       0x00000010
-		XFS_PTAG_SHUTDOWN_IOERROR       0x00000020
-		XFS_PTAG_SHUTDOWN_LOGERROR      0x00000040
-		XFS_PTAG_FSBLOCK_ZERO           0x00000080
-		XFS_PTAG_VERIFIER_ERROR         0x00000100
-
-	This option is intended for debugging only.
-
-  fs.xfs.irix_symlink_mode	(Min: 0  Default: 0  Max: 1)
-	Controls whether symlinks are created with mode 0777 (default)
-	or whether their mode is affected by the umask (irix mode).
-
-  fs.xfs.irix_sgid_inherit	(Min: 0  Default: 0  Max: 1)
-	Controls files created in SGID directories.
-	If the group ID of the new file does not match the effective group
-	ID or one of the supplementary group IDs of the parent dir, the
-	ISGID bit is cleared if the irix_sgid_inherit compatibility sysctl
-	is set.
-
-  fs.xfs.inherit_sync		(Min: 0  Default: 1  Max: 1)
-	Setting this to "1" will cause the "sync" flag set
-	by the xfs_io(8) chattr command on a directory to be
-	inherited by files in that directory.
-
-  fs.xfs.inherit_nodump		(Min: 0  Default: 1  Max: 1)
-	Setting this to "1" will cause the "nodump" flag set
-	by the xfs_io(8) chattr command on a directory to be
-	inherited by files in that directory.
-
-  fs.xfs.inherit_noatime	(Min: 0  Default: 1  Max: 1)
-	Setting this to "1" will cause the "noatime" flag set
-	by the xfs_io(8) chattr command on a directory to be
-	inherited by files in that directory.
-
-  fs.xfs.inherit_nosymlinks	(Min: 0  Default: 1  Max: 1)
-	Setting this to "1" will cause the "nosymlinks" flag set
-	by the xfs_io(8) chattr command on a directory to be
-	inherited by files in that directory.
-
-  fs.xfs.inherit_nodefrag	(Min: 0  Default: 1  Max: 1)
-	Setting this to "1" will cause the "nodefrag" flag set
-	by the xfs_io(8) chattr command on a directory to be
-	inherited by files in that directory.
-
-  fs.xfs.rotorstep		(Min: 1  Default: 1  Max: 256)
-	In "inode32" allocation mode, this option determines how many
-	files the allocator attempts to allocate in the same allocation
-	group before moving to the next allocation group.  The intent
-	is to control the rate at which the allocator moves between
-	allocation groups when allocating extents for new files.
-
-Deprecated Sysctls
-==================
-
-None at present.
-
-
-Removed Sysctls
-===============
-
-  Name				Removed
-  ----				-------
-  fs.xfs.xfsbufd_centisec	v4.0
-  fs.xfs.age_buffer_centisecs	v4.0
-
-
-Error handling
-==============
-
-XFS can act differently according to the type of error found during its
-operation. The implementation introduces the following concepts to the error
-handler:
-
- -failure speed:
-	Defines how fast XFS should propagate an error upwards when a specific
-	error is found during the filesystem operation. It can propagate
-	immediately, after a defined number of retries, after a set time period,
-	or simply retry forever.
-
- -error classes:
-	Specifies the subsystem the error configuration will apply to, such as
-	metadata IO or memory allocation. Different subsystems will have
-	different error handlers for which behaviour can be configured.
-
- -error handlers:
-	Defines the behavior for a specific error.
-
-The filesystem behavior during an error can be set via sysfs files. Each
-error handler works independently - the first condition met by an error handler
-for a specific class will cause the error to be propagated rather than reset and
-retried.
-
-The action taken by the filesystem when the error is propagated is context
-dependent - it may cause a shut down in the case of an unrecoverable error,
-it may be reported back to userspace, or it may even be ignored because
-there's nothing useful we can with the error or anyone we can report it to (e.g.
-during unmount).
-
-The configuration files are organized into the following hierarchy for each
-mounted filesystem:
-
-  /sys/fs/xfs/<dev>/error/<class>/<error>/
-
-Where:
-  <dev>
-	The short device name of the mounted filesystem. This is the same device
-	name that shows up in XFS kernel error messages as "XFS(<dev>): ..."
-
-  <class>
-	The subsystem the error configuration belongs to. As of 4.9, the defined
-	classes are:
-
-		- "metadata": applies metadata buffer write IO
-
-  <error>
-	The individual error handler configurations.
-
-
-Each filesystem has "global" error configuration options defined in their top
-level directory:
-
-  /sys/fs/xfs/<dev>/error/
-
-  fail_at_unmount		(Min:  0  Default:  1  Max: 1)
-	Defines the filesystem error behavior at unmount time.
-
-	If set to a value of 1, XFS will override all other error configurations
-	during unmount and replace them with "immediate fail" characteristics.
-	i.e. no retries, no retry timeout. This will always allow unmount to
-	succeed when there are persistent errors present.
-
-	If set to 0, the configured retry behaviour will continue until all
-	retries and/or timeouts have been exhausted. This will delay unmount
-	completion when there are persistent errors, and it may prevent the
-	filesystem from ever unmounting fully in the case of "retry forever"
-	handler configurations.
-
-	Note: there is no guarantee that fail_at_unmount can be set while an
-	unmount is in progress. It is possible that the sysfs entries are
-	removed by the unmounting filesystem before a "retry forever" error
-	handler configuration causes unmount to hang, and hence the filesystem
-	must be configured appropriately before unmount begins to prevent
-	unmount hangs.
-
-Each filesystem has specific error class handlers that define the error
-propagation behaviour for specific errors. There is also a "default" error
-handler defined, which defines the behaviour for all errors that don't have
-specific handlers defined. Where multiple retry constraints are configuredi for
-a single error, the first retry configuration that expires will cause the error
-to be propagated. The handler configurations are found in the directory:
-
-  /sys/fs/xfs/<dev>/error/<class>/<error>/
-
-  max_retries			(Min: -1  Default: Varies  Max: INTMAX)
-	Defines the allowed number of retries of a specific error before
-	the filesystem will propagate the error. The retry count for a given
-	error context (e.g. a specific metadata buffer) is reset every time
-	there is a successful completion of the operation.
-
-	Setting the value to "-1" will cause XFS to retry forever for this
-	specific error.
-
-	Setting the value to "0" will cause XFS to fail immediately when the
-	specific error is reported.
-
-	Setting the value to "N" (where 0 < N < Max) will make XFS retry the
-	operation "N" times before propagating the error.
-
-  retry_timeout_seconds		(Min:  -1  Default:  Varies  Max: 1 day)
-	Define the amount of time (in seconds) that the filesystem is
-	allowed to retry its operations when the specific error is
-	found.
-
-	Setting the value to "-1" will allow XFS to retry forever for this
-	specific error.
-
-	Setting the value to "0" will cause XFS to fail immediately when the
-	specific error is reported.
-
-	Setting the value to "N" (where 0 < N < Max) will allow XFS to retry the
-	operation for up to "N" seconds before propagating the error.
-
-Note: The default behaviour for a specific error handler is dependent on both
-the class and error context. For example, the default values for
-"metadata/ENODEV" are "0" rather than "-1" so that this error handler defaults
-to "fail immediately" behaviour. This is done because ENODEV is a fatal,
-unrecoverable error no matter how many times the metadata IO is retried.
diff --git a/MAINTAINERS b/MAINTAINERS
index d0ed73599..66e972e9a 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -17364,7 +17364,7 @@  L:	linux-xfs@vger.kernel.org
 W:	http://xfs.org/
 T:	git git://git.kernel.org/pub/scm/fs/xfs/xfs-linux.git
 S:	Supported
-F:	Documentation/filesystems/xfs.txt
+F:	Documentation/filesystems/xfs.rst
 F:	fs/xfs/
 
 XILINX AXI ETHERNET DRIVER